Transistors, such as metal oxide semiconductor field-effect transistors (MOSFETs), are the core building block of the vast majority of semiconductor devices. Some semiconductor devices, such as high performance processor devices, can include millions of transistors. For such devices, decreasing transistors size, and thus increasing transistor density, has traditionally been a high priority in the semiconductor manufacturing industry.
A FinFET is a type of transistor that can be fabricated using very small scale processes. FIG. 1 is a simplified perspective view of a FinFET 100, which is formed on a semiconductor wafer substrate 102. A FinFET is named for its use of one or more conductive fins 104. As shown in FIG. 1, each fin 104 extends between a source region 106 and a drain region 108 of FinFET 100. FinFET 100 includes a gate structure 110 that is formed across fins 104. The surface area of the fins 104 in contact with gate structure 110 determines the effective channel of FinFET 100.
In addition to the fins, source, and drain regions, some FinFET architectures incorporate resistors. One type of resistor is known as a “diffused” resistor, wherein the resistive material is incorporated into the semiconductor substrate via molecular diffusion mechanisms. In process flows wherein the fin structures are grown epitaxially via epitaxial growth processes, it has been observed that if a diffused resistor is present in the region wherein epitaxial silicon is grown, then the growth occurs substantially uncontrollably, which can lead to large variability in the resistance of the device.
Accordingly, it is desirable to provide improved FinFET structures and methods for fabricating FinFET structures, which can allow for controllable epitaxial silicon growth in areas where a diffused resistor has been provided. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings, the brief summary, and this background of the invention.